Coupling elements for transmitting optical or electrical signals are well known in the field of medicine. In a specific area of application, they are used to transmit signals from the inside of the body of a patient to the outside of the body of the patient and/or vice versa. This is required, for example, when a medical device, such as an insulin pump, is implanted into the patient's body, and the device needs to be addressed or accessed from the outside, for example for control purposes, and/or needs to be capable of emitting signals to the outside, for example to indicate the status of the device. For this purpose, the cable is passed from the implanted device to the outside of the body through an orifice in the body and the coupling element is coupled to a matching counterpart that, in turn, may be connected to a control device and/or an analytical device.